Partial Sequence of the Alpha-Tubulin Gene From Histomonas meleagridis Isolates From

Histomonas meleagridis, the causative agent of histomoniasis, is a protozoan parasite classified in the Dientamoebidae (order Tritrichomonadida). The a-tubulin gene of 7 H. meleagridis isolates originating from either domestic chickens or turkeys from the United States was amplified by nested PCR and sequenced. A 91.4-99.8% nucleotide identity was shared among the 7 different sequences, and phylogenetic analysis disclosed that the 7 isolates were divided into at least 3 clades. These sequences had a 91-99% nucleotide identity and a 96 100% amino acid identity compared with 3 H. meleagridis a-tubulin sequences obtained from isolates originating from turkeys in Germany. Further a-tubulin gene analysis from species in the Dientamoebidae will be useful in elucidating the evolutionary relationship of these protozoans. Histomonas meleagridis, the causative agent of histomoniasis (blackhead disease), is a parabasalid protozoan parasite of the Dientamoebidae (order Tritrichomonadida: class Tritrichomonadea) (Cepicka et al., 2010). Dientamoebids include species of Dientamoeba, Protrichomonas, Histom onas, and Parahistomonas and are characterized as uninucleate to